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Punctures and flint

Tony666Tony666 Posts: 274
edited February 2009 in Road beginners
Punctures seems to be a way of life for me at the moment. Probably something to do with the lightweight tyres that I am using. Although I popped down to my local bike shop on Friday and the guy there was saying that there is a lot of rubbish on the roads at the moment, including flint. Flint?! How the heck does that get there? I thought this was 2009, not 10,000 BC. Or maybe the flint has something to do with the recent road gritting that's been going on due to freezing temperatures. I doubt it somehow although it would never surprise me if the Local Authority turned round one day said they had gritted the roads with a nice sharp stone that can easily cut through tyres.

It is now a case of new tyres for old, and I have replaced them with Bontrager Race Lites.

So now if I get mugged all I need to do is simply shout "Stab the tyres, stab the tyres" and can then laugh and ride off into the sunset as they have a Kevlar belt. But will they stop the flint and punctures? I guess I'll find out tomorrow.


  • chuckcorkchuckcork Posts: 1,471
    Flints is a generic term for sharp edged stones, not flint you'd find used in walls. Perhaps not quite as sharpa s glass, but if you leave them embedded they will slowly work they're way into and through the tyre to puncture.

    And if your kevlar tyres were stabbed in the side, the tube would be punctured as the Kevlar is only there for the running section of the tyre, not the sidewall. I've recently thrown away a tyre because of a blow-out due to a cut in the sidewall....
    'Twas Mulga Bill, from Eaglehawk, that caught the cycling craze....
  • I'm not sure you're right, flint is a specific form of chert found in chalk apparently. Part of the quartz family (yes all lifted of wikipedia 8) )

    it is very brittle, so particularly with the recent frosts some will have been cracked and the small shards are incrediably hard and sharp. They're the only things i've had puncture specialized fatboys which have an enormous kevlar belt in.

    Get tonnes of small pieces on the road at home as I live near the white cliffs!!!! I've even had a shard fly into my eye, and i couldnt' get it out until i arrived at work with a mirror, that was not fun.
  • Tony666Tony666 Posts: 274
    Elementary my dear Watson as according to the Bontrager blurb "the bead-to-bead woven construction reduces sidewall cuts". Luckily it also says "the Hardcase's high-speed tread compound provides optimal traction and low rolling resistance ". But has anyone here actuualy tried them?
    I've even had a shard fly into my eye, and i couldnt' get it out until i arrived at work with a mirror, that was not fun.
    :( Have you seen the thread about worst accidents!
  • I'd say flint shards will still puncture a kevlar belted tyre from my experience, but you shouldn't get anything else through them other than the occasional pinch flats from pot-holes.

    I've found that you do best to try and avoid the flint, it is normally quite easy to see (esp. when it is in your eye) also avoid gravelly bits as it often will be lurking there for your rubber...
  • pbracingpbracing Posts: 231
    I thought there was a lot of flint in East Anglia/ Essex (the old churches are all flint covered), and with the heavy rain after the snow, it's washed out of the fields onto the roads. Possibly.
    Why not? My bikes.
    Summer & dry days ... /Trek1.jpg

    Wet winter days & going the shops runaround ... rello1.jpg
  • Zendog1Zendog1 Posts: 816
    There certainly is a lot of flint in East Anglia :( and most of the rest of the south.

    Round here it does'nt need to wash out. The farmers thoughfully transport lots of it from the fields on muddy tractor tyres and spread it liberally on the lanes.

    Kelvar helps but a small shard in a tire slit will get through eventually is my experience.
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